Question

Without using trigonometric tables, prove that:
cos²57° - sin²33° = 1​

Answer 1

Step-by-step explanation:

cos²A=1-sin²A. cos² 57 +1- sin² 33=1. cos² 57-sin²33=0. sin²33-sin²33=0. 0 =0. HENCE PROVED.... HOPE IT'S HELPFUL.